Exaggerated endurance sports can seriously damage the heart

Intense endurance sports can damage hearts
Active exercise and sports are basic rules of conduct that have been proven to lead to a longer and healthier life. But if we overdo it, sport can also harm health - and even massively, as a study by the University Hospital Hamburg-Eppendorf showed. Our heart can be severely damaged if we constantly exceed our performance limit. Especially men are affected.

Permanently intense sport can be unhealthy
Sportsman, watch out: too intense sport can be unhealthy! As a research group from the University Medical Center Hamburg-Eppendorf (UKE) reports in the scientific journal JACC: Cardiovascular Imaging, male triathletes may risk their heart health if they put too much stress on the competition. In female triathletes, the researchers could not detect such negative effects.

Those who constantly exceed their performance limits risk scars at heart. (Image: Glebstock / fotolia.com)

"We have indications that cardiac muscle scarring, which is observed only in male subjects, has something to do with competition. The greater the load, the longer the distances covered in the competition, the higher the probability of damage to the heart muscle, "explains the head of the working group, Prof. Dr. med. Gunnar Lund from the UKE Department of Diagnostic and Interventional Radiology and Nuclear Medicine. "There is probably a personal exposure limit. If it is exceeded, the heart can be damaged. "

Obviously healthy athletes with scarring on the heart muscle
As part of a scientific study, the UKE team examined 54 male and 29 female triathletes - all ambitious and healthy recreational athletes who train at least ten hours a week and an average of 43 years (plus / minus ten years) are old. The physicians examined the triathletes after administration of contrast medium with cardio-magnetic resonance imaging (MRI).

The result: contrast media was found in left ventricular muscle in ten male participants who had previously been swimming and / or cycling longer distances. "The contrast agent shows scarring of the heart muscle, called myocardial fibrosis, which may be associated with the onset of life-threatening cardiac arrhythmias," explains Prof. Lund.

An existing and previously unrecognized myocarditis may be a possible cause of the noted scarring: "In the normal population occurs a myocarditis with a frequency of three to four percent. By contrast, 17 percent of our male study participants are affected, which means that there are other causes. "An overload of the heart due to too much sport at the performance limit is conceivable. Those affected had increased heart muscle mass and in part too high blood pressure under stress, which may have favored the heart muscle damage.

Prof. Lund: "Similar to a poorly set engine, which runs permanently on high tours, so the heart can permanently harm itself." In addition, the male hormone testosterone could still play a role. "That would explain why we have found no fibrotic changes in the heart muscle in women. But maybe women are naturally better protected for some other reason - or they are just cleverer and less exhausted than men. "

However, recreational athletes do not have to worry about the doctor: "At a moderate level, sport is undoubtedly healthy and life-prolonging." Anyone who puts a lot of strain on themselves should have their heart examined at least once, according to Prof. Lund. "Best with a cardiac MRI as we used it. This is the only technique that can detect the scarring of the heart muscles in athletes. An ultrasound examination or ECG is not enough for that. "(Sb, pm)

Literature:
Tahir, E. et al., Myocardial Fibrosis in Competitive Triathletes Detected by Contrast-Enhanced CMR Correlates with Exercise-Induced Hypertension and Competition History. JACC: Cardiovascular Imag-ing, 2017. DOI: 10.1016 / j.jcmg.2017.09.016